1. Field of the Invention
The present invention pertains to a pipe elevator assembly, primarily for use in the oil and gas drilling industry. More particularly, the present invention pertains to an elevator assembly having a reversible inner insert member that permits said elevator assembly to grip and accommodate multiple different types and configurations of pipe and/or threaded connections.
2. Brief Description of the Prior Art
In the oil well drilling industry, an elevator assembly (sometimes also referred to as a “set of elevators”) is a mechanism that can be used to lift and support pipe and/or other tubular members. The elevator assembly, which is typically suspended from a rig's traveling block or other hoisting device using bails or linkages, is typically used to grip the external surface of pipe other tubular goods to be lifted within a drilling rig derrick. Once the elevator assembly is securely locked in place around the external surface of the pipe, the traveling block or other hoisting device can be raised in order to lift such pipe within a rig derrick and/or lower such pipe into a wellbore.
Although elevator assemblies come in many different shapes, sizes and configurations, one common style of elevator assembly is a latching-type elevator. Such an elevator generally comprises two opposing semi-cylindrical body members that are hingedly attached to each other; said members can be selective latched in a closed (joined) configuration, or unlatched in an open or spread apart configuration.
When unlatched, said opposing body members can be spread apart or swung open relative to each other to permit placement of such elevator body members around the outer or external surface of a section of pipe. When latched, said hinged opposing members can be temporarily locked together in mating relationship to form a ring-like load bearing structure that can be used to securely grip against the external surface of a section of pipe.
When multiple pipe sections are screwed together or otherwise joined to form an elongate pipe string, an elevator assembly can be used to grip an uppermost pipe section of the string and support the entire weight of such pipe string. In such cases, an elevator assembly typically must be capable of supporting relatively heavy loads, since such pipe strings can often be quite heavy. However, in certain instances, elevator assemblies are used to grip and support single pipe sections or very short pipe strings; in such cases, so-called single joint elevators are particularly useful for gripping and hoisting relatively light pipe sections.
Such single joint elevator assemblies, which are frequently smaller and lighter than conventional elevator assemblies, typically comprise removable components known as inserts; a separate insert is disposed on the inner surface of each opposing elevator member. Such inserts cooperate to form a desired profile that generally conforms to the shape of the outer surface of the particular section of pipe to be gripped by said elevator assembly. Further, such inserts each typically define at least one upwardly facing load-bearing shoulder or support surface designed to support the weight of a pipe section (and, more specifically, typically the lower surface of a threaded connection or threaded collar of such pipe section) to be gripped and lifted by said elevators. Elevator inserts are typically removable so that a single elevator assembly can be used with multiple sets of interchangeable inserts in order to fit many different types of pipe, or tubular goods having different outer profiles.
Thus, in order to function properly, a single set of opposing inserts must cooperate in order to closely conform to the outer surface of a particular type or style of pipe (including, without limitation, any integral threaded connection member or threaded collar). As such, a single set of inserts that conforms to one particular type of pipe section may not conform to another type of pipe section having a different outer configuration. For example, a single set of conventional elevator inserts designed for use with coupled pipe (that is, externally threaded pipe sections joined using internally threaded pipe couplings) will not work with pipe equipped with so-called premium or integrally formed threaded connections, and vice versa.
Thus, there is a need for an elevator system having interchangeable inserts. Said inserts should be quickly and efficiently removed and replaced. Further, such inserts should be compatible with multiple different styles or configurations of pipe.